Anionic direct dye having a tetraalkylammonium counterion, dyeing composition comprising them and method for dyeing keratinous fibres starting from these dyes

ABSTRACT

The invention relates to the dyeing of human keratinous fibres, in particular the hair, using anionic direct dyes or acid dyes having a tetraalkylammonium counterion of formula (I) with Col (−) m. R 1 , R 2 , R 3 , R 4 , m, and n as defined in the description. A subject-matter of the invention is a dyeing composition comprising an anionic dye of formula (I) and a method for dyeing keratinous fibres, such as the hair, employing the said composition. A subject-matter of the invention is likewise novel dyes of formula (I) and their uses for the colouring of keratinous fibres. This composition makes it possible to obtain a chromatic, powerful and particularly persistent colouring on keratinous fibres.

The invention relates to the dyeing of human keratinous fibres usinganionic direct dyes having a tetraalkylammonium counterion.

It is known to dye keratinous fibres, in particular the hair, by directdyeing. The method conventionally used in direct dyeing consists inapplying, to the keratinous fibres, direct dyes, which are coloured andcolouring molecules having an affinity for fibres, in allowing them todiffuse and in then rinsing the fibres.

The direct dyes which are conventionally used are, for example, dyes ofthe nitrobenzene type, anthraquinone dyes, nitropyridines or dyes of theazo, xanthene, acridine, azine or triarylmethane type. These dyes can beanionic, cationic or neutral. Anionic dyes or “acid dyes” are known notto be persistent on keratinous fibres and to have a low colouring power.In addition, they are easily absorbed by the skin as the hair, which hasthe effect of colouring the scalp when the hair is dyed. For thesereasons, anionic dyes are not used to any great extent as dye for hairdyeing (see, for example, Kirk Othmer Encyclopedia of ChemicalTechnology—“Hair Preparation”, pt. 4, p. 18; Published Online 18september 2009, DOI: 10.1002/0471238961.0801091816150812.a01.pub2;Ullmann's Encyclopedia of Industrial Chemistry, “Hair Preparation”, pt.5.2.3, p. 21; Published Online: 15 july 2006, DOI:10.1002/14356007.a12_(—)571.pub2).

The aim of the present invention is to provide novel dyes for humankeratinous fibres, such as the hair, which exhibit improved dyeingproperties, in particular a colouring of the hair which is powerful,chromatic and/or persistent with regard to external attacks, inparticular to shampooing operations, without causing excessive stainingof the scalp. The invention is also targeted at making available hairdyes with a low colouring selectivity between the root and the tip,which do not damage the keratinous fibres, which do not detrimentallyaffect their cosmetic properties and which produce less staining of theskin.

These aims are achieved by the present invention, a subject-matter ofwhich is a method for dyeing keratinous fibres which consists inapplying, to the said fibres, a composition comprising one or moreanionic dyes of formula (I):

and their optical isomers, geometric isomers and solvates, such ashydrates; in which formula (I):

-   -   R₁, R₂, R₃ and R₄, which are identical or different, represent a        group chosen from i) (C₁-C₂₀)alkyl; ii) (C₂-C₂₀)alkenyl; it        being possible for the alkyl or alkenyl group of the groups        of i) and ii) to be interrupted by one or more identical or        different heteroatoms chosen from oxygen, sulphur or N(Ra), with        Ra representing a hydrogen atom or an alkyl group; preferably,        R₁, R₂, R₃ and R₄ are identical and more particularly represent        a linear (C₁-C₅)alkyl group, such as methyl, ethyl, propyl or        butyl;    -   Col⁽⁻⁾ _(m) represents the anionic part of the anionic direct        dye or acid dye comprising, in its structure, at least one        sulphonate group and/or at least one carboxylate group and        comprising m anionic charge(s);    -   m and n, which are identical or different, represent an integer        between 1 and 10 inclusive;        it being understood that:    -   when the anionic part of the anionic direct dye comprises a        sulphonate group or a carboxylate group, then m=n=1; and    -   when the anionic part of the anionic direct dye comprises        anionic groups other than the sulphonate or carboxylate group,        it is combined with one or more cationic counterions, organic,        inorganic or R₁R₂R₃R₄N⁺, making it possible to achieve        electrical neutrality of the formula (I).

Another subject-matter of the invention is the use of at least oneanionic dye of formula (I) as defined above to dye keratinous fibres,such as the hair.

Another subject-matter of the invention is the use of at least onefluorescent anionic dye of formula (I), particularly in the range of theorangey colours, for the purpose of optically lightening dark keratinousfibres, such as hair with a height of tone of less than or equal to 6and preferably of less than or equal to 4, this being achieved even inthe absence of a chemical oxidizing agent other than atmospheric oxygen.

Another subject-matter of the invention is a method for dyeingkeratinous fibres employing one or more anionic dyes of formula (I) asdefined above.

Another subject-matter of the invention is an anionic dye of formula (I)as described above; preferably, the said dye of formula (I) is such thatthe R₁, R₂, R₃ and R₄ radicals are identical and the said dye of formula(I) is different from the dyes of following formulae (a) to (u):

Another subject-matter of the invention is a dyeing compositioncomprising, in an appropriate cosmetic medium, at least one anionic dyeof formula (I); preferably, the said anionic dye of formula (I) is suchthat the R₁, R₂, R₃ and R₄ radicals are identical, and the said dye offormula (I) is different from the dyes of formulae (a) to (u) as definedabove.

With the dyes of the invention, it is possible to improve the dyeingproperties of anionic dyes, in particular in terms of chromaticity,power and persistence, by replacing “conventional” cationic counterions,such as alkali metal or alkaline earth metal cations, by an organiccation of tetraalkylammonium type, preferably having a C₁-C₆ chain, suchas butyl.

The anionic dyes of formula (I) according to the invention arefurthermore stable with regard to oxidizing agents and exhibit asatisfactory solubility in cosmetic dyeing media.

The term “dark hair” is understood to mean hair which is naturally orartificially dark and which has a height of tone of less than or equalto 6 (dark blond) and preferably of less than or equal to 4 (chestnut).The notion of “tone” is based on the classification of natural hues, onetone separating each hue from that which immediately follows or precedesit. This definition and the classification of natural hues are wellknown to professionals in hairstyling and are published in the work“Science des traitements capillaries” [The Science of Hair Care] byCharles Zviak, 1988, published by Masson, pp. 215 and 278. The heightsof tone range from 1 (black) to 10 (very light blonde), one unitcorresponding to one tone; the higher the figure, the lighter the hue.

Within the meaning of the present invention and unless otherwiseindicated:

-   -   the “aryl” or “heteroaryl” radicals or the aryl or heteroaryl        part of a radical can be substituted by at least one substituent        carried by a carbon atom chosen from:        -   a C₁-C₁₆, preferably C₁-C₈, alkyl radical optionally            substituted by one or more radicals chosen from hydroxyl,            C₁-C₂ alkoxy, C₂-C₄(poly)hydroxyalkoxy, acylamino or            substituted amino radicals, the substituted amino radical            being substituted by two identical or different C₁-C₄ alkyl            radicals optionally carrying at least one hydroxyl group or            it being possible for the two radicals to form, with the            nitrogen atom to which they are attached, a saturated or            unsaturated 5- to 7-membered, preferably 5- or 6-membered,            heterocycle which is optionally substituted and which            optionally comprises another heteroatom identical to or            different from nitrogen;        -   a halogen atom, such as chlorine, fluorine or bromine;        -   a hydroxyl group;        -   a C₁-C₂ alkoxy radical;        -   a C₂-C₄ (poly)hydroxyalkoxy radical;        -   an amino radical;        -   a nitro radical;        -   a 5- or 6-membered heterocycloalkyl radical;        -   an optionally cationic 5- or 6-membered heteroaryl radical,            preferably an imidazolium radical, which is optionally            substituted by a (C₁-C₄)alkyl radical, preferably a methyl            radical;            -   an amino radical substituted by one or two identical or                different C₁-C₆ alkyl radicals which optionally carry at                least            -   i) one hydroxyl group,            -   ii) one amino group optionally substituted by one or two                C₁-C₃ alkyl radicals which are optionally substituted,                it being possible for the said alkyl radicals to form,                with the nitrogen atom to which they are attached, a                saturated or unsaturated 5- to 7-membered heterocycle                which is optionally substituted and which optionally                comprises at least one other heteroatom identical to or                different from nitrogen,        -   an acylamino (—NR—C(O)R′) radical, in which the R radical is            a hydrogen atom or a C₁-C₄ alkyl radical optionally carrying            at least one hydroxyl group and the R′ radical is a C₁-C₂            alkyl radical;        -   a carbamoyl ((R)₂N—C(O)—) radical, in which the R radicals,            which are identical or different, represent a hydrogen atom            or a C₁-C₄ alkyl radical optionally carrying at least one            hydroxyl group;        -   a carboxylic acid or ester (—O—C(O)R′ or —C(O)OR′) radical,            in which the R′ radical is a hydrogen atom or a C₁-C₄ alkyl            radical optionally carrying at least one hydroxyl group and            the R′ radical is a C₁-C₂ alkyl radical;        -   it being possible for the carboxyl radical to be in the acid            or salified form (preferably salified with an alkali metal            or a substituted or unsubstituted ammonium);        -   an alkylsulphonylamino (R′SO₂—NR—) radical, in which the R            radical represents a hydrogen atom or a C₁-C₄ alkyl radical            optionally carrying at least one hydroxyl group and the R′            radical represents a C₁-C₄ alkyl radical or a phenyl            radical;        -   an aminosulphonyl ((R)₂N—SO₂—) radical, in which the R            radicals, which are identical or different, represent a            hydrogen atom or a C₁-C₄ alkyl radical optionally carrying            at least one hydroxyl group,        -   a cyano (CN) group;        -   a (poly)haloalkyl group, preferably trifluoromethyl (CF₃);    -   the cyclic or heterocyclic part of a nonaromatic radical can be        substituted by at least one substituent carried by a carbon atom        chosen from the following groups:        -   hydroxyl;        -   C₁-C₄ alkoxy or C₂-C₄ (poly)hydroxyalkoxy;        -   alkylcarbonylamino (RC(O)—NR′—), in which the R′ radical is            a hydrogen atom or a C₁-C₄ alkyl radical optionally carrying            at least one hydroxyl group and the R radical is a C₁-C₂            alkyl radical or an amino radical substituted by two            identical or different C₁-C₄ alkyl groups optionally            carrying at least one hydroxyl group, it being possible for            the said alkyl radicals to form, with the nitrogen atom to            which they are attached, a saturated or unsaturated 5- to            7-membered heterocycle which is optionally substituted and            which optionally comprises at least one other heteroatom            identical to or different from nitrogen;        -   alkylcarbonyloxy (RC(O)—O—), in which the R radical is a            C₁-C₄ alkyl radical or an amino radical substituted by two            identical or different C₁-C₄ alkyl groups optionally            carrying at least one hydroxyl group, it being possible for            the said alkyl radicals to form, with the nitrogen atom to            which they are attached, a saturated or unsaturated 5- to            7-membered heterocycle which is optionally substituted and            which optionally comprises at least one other heteroatom            identical to or different from nitrogen;        -   alkoxycarbonyl (RO—C(O)—), in which the R radical is a C₁-C₄            alkyl radical or an amino radical substituted by two            identical or different C₁-C₄ alkyl groups optionally            carrying at least one hydroxyl group, it being possible for            the said alkyl radicals to form, with the nitrogen atom to            which they are attached, a saturated or unsaturated 5- to            7-membered heterocycle which is optionally substituted and            which optionally comprises at least one other heteroatom            identical to or different from nitrogen;    -   a cyclic or heterocyclic radical or a nonaromatic part of an        aryl or heteroaryl radical can also be substituted by one or        more oxo groups;    -   an “aryl” radical represents a monocyclic or fused or nonfused        polycyclic group comprising from 6 to 22 carbon atoms, at least        one ring of which is aromatic; in particular, the aryl radical        is a phenyl, biphenyl, naphthyl, indenyl, anthracenyl or        tetrahydronaphthyl and more preferably phenyl;    -   a “heteroaryl” radical represents a monocyclic or fused or        nonfused polycyclic group comprising from 5 to 22 ring members        and from 1 to 6 heteroatoms chosen from nitrogen, oxygen,        sulphur and selenium atoms, at least one ring of which is        aromatic; preferably, a heteroaryl radical is chosen from        acridinyl, benzimidazolyl, benzobistriazolyl, benzopyrazolyl,        benzopyridazinyl, benzoquinolyl, benzothiazolyl, benzotriazolyl,        benzoxazolyl, pyridinyl, tetrazolyl, dihydrothiazolyl,        imidazopyridinyl, imidazolyl, indolyl, isoquinolyl,        naphthoimidazolyl, naphthooxazolyl, naphthopyrazolyl,        oxadiazolyl, oxazolyl, oxazolopyridyl, phenazinyl,        phenooxazolyl, pyrazinyl, pyrazolyl, pyrilyl, pyrazoyltriazyl,        pyridyl, pyridinoimidazolyl, pyrrolyl, quinolyl, tetrazolyl,        thiadiazolyl, thiazolyl, thiazolopyridinyl, thiazoylimidazolyl,        thiopyrylyl, triazolyl and xanthyl and its ammonium salt;    -   a “cyclic” radical is a “cycloalkyl” radical, i.e. a monocyclic        or fused or nonfused nonaromatic radical which comprises from 5        to 22 carbon atoms and which can comprise from one to several        unsaturations, such as cyclohexyl or cyclopentyl;    -   a “heterocyclic” radical is a monocyclic or fused or nonfused        polycyclic nonaromatic radical which comprises from 5 to 22 ring        members and which comprises from 1 to 6 heteroatoms chosen from        nitrogen, oxygen, sulphur and selenium atoms, morpholinyl,        thiomorpholinyl, piperidinyl, piperazinyl, pyrrolidinyl,        tetrahydrofuranyl, tetrahydrothiophenyl, azepanyl, thioazepanyl;        preferably pyrrolidinyl and morpholino;    -   an “alkyl” radical is a linear or branched C₁-C₁₆, preferably        C₁-C₈ and in particular C₁-C₄ hydrocarbon radical, such as        methyl or ethyl;    -   an “alkenyl” radical is a linear or branched C₂-C₂₀ hydrocarbon        radical comprising one or more conjugated or nonconjugated        double bonds, in particular a C₄-C₁₀ hydrocarbon radical        comprising one, two or three double bonds, preferably a single        double bond;    -   the expression “optionally substituted” assigned to the alkyl        radical implies that the said alkyl radical can be substituted        by one or more radicals chosen from the following radicals: i)        hydroxyl, ii) C₁-C₄ alkoxy, iii) acylamino, iv) amino optionally        substituted by one or two identical or different C₁-C₄ alkyl        radicals, it being possible for the said alkyl radicals to form,        with the nitrogen atom which carries them, a 5- to 7-membered        heterocycle optionally comprising another heteroatom identical        to or different from nitrogen;    -   an “alkoxy” radical is an alkyl-oxy or alkyl-O— radical for        which the alkyl radical is a linear or branched C₁-C₁₆,        preferably C₁-C₈ and in particular C₁-C₄ hydrocarbon radical,        such as methoxy or ethoxy, and, when the alkoxy group is        optionally substituted, this implies that the alkyl group is        optionally substituted as defined above;    -   a “(poly)haloalkyl” radical is an “alkyl” radical as defined        above in which one or more hydrogen atoms are substituted or        replaced by one or more halogen atoms, such as fluorine,        chlorine or bromine atoms; mention may be made, as        polyhaloalkyl, of the trifluoromethyl group;    -   an “alkylthio” radical is an alkyl-S— radical for which the        alkyl radical is a linear or branched C₁-C₁₆, preferably C₁-C₈        and in particular C₁-C₄ hydrocarbon radical, such as methylthio        or ethylthio, and, when the alkylthio group is optionally        substituted, this implies that the alkyl group is optionally        substituted as defined above;    -   a cationic counterion is organic or inorganic preferably chosen        from alkali metal or alkaline earth metal inorganic cations,        such as Na, Mg, K and Ca, and organic cations, such as ammonium        NH₄ ⁺;    -   when the expression “at least one” is employed, this implies        “one or more”.

Furthermore, unless otherwise indicated, the limits delimiting theextent of a range of values are included within this range of values.

According to the present invention, the term “dye” is understood to meana compound which has the ability to dye and which is provided as acoloured compound observable by eye, i.e. which absorbs light at awavelength included in UV and visible radiation, at a wavelength λ_(abs)of between 250 and 800 nm, particularly in the visible spectrum between400 and 700 nm.

The term “fluorescent dye” is understood to mean a dye as defined abovewhich, in addition to the fact of being coloured, is fluorescent, thatis to say that it has the ability to reemit at least a portion of thelight absorbed in the visible region at a greater wavelength than thatabsorbed. In particular, the fluorescent dye is capable of absorbing UVor visible radiation at a wavelength λ_(abs) of between 250 and 800 nmand of reemitting in the visible region at an emission wavelength λ_(em)of between 400 and 800 nm. Preferably, the fluorescent dye is a dye inthe range of the orangey colours.

I. Dyes of Formula (I)

The anionic direct dyes of formula (I) according to the invention“result” from dyes commonly known as “acid dyes” for their affinity withalkaline substances (see, for example, “Industrial Dyes, Chemistry,Properties, Application”, edited by Klaus Hunger, Wiley-VCH Verlag GmbH& Co. KGaA, Weinheim, 2003). Acid or anionic dyes are known in theliterature (see, for example “Ullman's Encyclopedia of IndustrialChemistry”, Azo Dyes, 2005, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim,10.1002/14356007.a03 245, point 3.2; ibid, Textile Auxiliaries, 2002,Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 10.1002/14356007.a26 227,and “Ashford's Dictionary of Industrial Chemicals, Second Edition”, p.14-p. 39, 2001).

The term “anionic direct dyes” is understood to mean any direct dyecomprising, in its structure, at least one sulphonate group SO₃ ⁻ and/orat least one carboxylate group C(O)O⁻ and optionally one or more anionicgroups G⁻, with G⁻, which are identical or different, representing ananionic group chosen from alkoxide O⁻, thiolate S, carboxylate andthiocarboxylate: C(Q)Q′⁻, with Q and Q′, which are identical ordifferent, representing an oxygen or sulphur atom; preferably, G⁻represents a carboxylate, i.e. Q and Q′ represent an oxygen atom.

In the formula (I) of the invention, the Col⁽⁻⁾ _(m) radical representsthe anionic part of the “acid dyes” or of the anionic direct dyes which“results” from the said acid dyes or from the said anionic direct dyes.The dyes of the invention resulting from the said acid dyes or from thesaid anionic direct dyes thus comprise at least one R₁R₂R₃R₄N⁺ cationiccounterion as defined above; preferably tetrabutylammonium.

Preferably, Col⁽⁻⁾ _(m) comprises, in its structure:

-   -   at least one sulphonate group and at least one (hetero)aryl        group, it being understood that at least one sulphonate group is        directly connected to a (hetero)aryl group, preferably an aryl        group, such as phenyl or benzo; and    -   optionally one or more anionic groups G, as defined above.

According to another preferred embodiment of the invention, Col⁽⁻⁾ _(m)comprises, in its structure:

-   -   at least one carboxylate group and at least one (hetero)aryl        group, it being understood that at least one carboxylate group        is directly connected to a (hetero)aryl group, preferably an        aryl group, such as phenyl or benzo; and    -   optionally one or more anionic groups G, as defined above.

According to yet another preferred embodiment of the invention, Col⁽⁻⁾_(m) comprises, in its structure:

-   -   at least one sulphonate group, at least one carboxylate group        and at least one (hetero)aryl group, it being understood that at        least one sulphonate or carboxylate group is directly connected        to a (hetero)aryl group, preferably an aryl group, such as        phenyl or benzo; and    -   optionally one or more anionic groups G⁻, as defined above.

According to a specific embodiment of the invention, the dyes of formula(I) are such that m is equal to n.

An advantageous alternative form of the invention relates to the dyes offormula (I) for which m and n have the values 1, 2 or 3.

Preferably, when compound of formula (I) according to the invention isderived from hydrazono anionic dyes thus it neither comprise a1,5-dioxocyclohex-2-enyl group nor a benzimidazolopyridone group. Morepreferably, compound of formula (I) does not bear a hydrazono group.

The preferred anionic dyes of formula (I) of the invention are chosenfrom acid nitro direct dyes, acid azo dyes, acid azine dyes, acidtriarylmethane dyes, acid indoamine dyes, acid anthraquinone dyes,indigoids and acid natural dyes, each of these dyes having at least onesulphonate or carboxylate group having a cationic counterion R₁R₂R₃R₄N⁺as defined above; preferably tetrabutylammonium sulphonate orcarboxylate.

According to a specific form of the invention, the ammonium counterionof the dye of formula (I) of the invention is such that the R₁, R₂, R₃and R₄ radicals are identical.

According to another advantageous embodiment of the invention, R₁, R₂,R₃ and R₄ are linear.

According to another specific form of the invention, R₁, R₂, R₃ and R₄are chosen from i) (C₁-C₆)alkyl; ii) (C₂-C₆)alkenyl; it being possiblefor the alkyl or alkenyl group of the groups of i) and ii) to beinterrupted by one or more identical or different heteroatoms chosenfrom oxygen, sulphur or N(Ra), with Ra representing a hydrogen atom oran alkyl group; preferably, R₁, R₂, R₃ and R₄ are identical and moreparticularly represent a linear (C₁-C₆)alkyl group, such as methyl,ethyl, propyl or butyl.

According to yet another specific form of the invention, R₁, R₂, R₃ andR₄ are fatty chains, i.e. chosen from i) (C₈-C₂₀)alkyl; ii)(C₈-C₂₀)alkenyl; it being possible for the alkyl or alkenyl group of thegroups of i) and ii) to be interrupted by one or more identical ordifferent heteroatoms chosen from oxygen, sulphur or N(Rα), with Rαrepresenting a hydrogen atom or an alkyl group; preferably, R₁, R₂, R₃and R₄ are identical and more particularly represent a linear(C₈-C₂₀)alkyl group.

Mention may be made, as anionic dyes according to the invention, of thedyes of following formulae (II), (II′), (III), (III′), (IV), (IV′), (V),(V′), (VI), (VII), (VIII) and (IX):

a) Diaryl Anionic Azo Dyes of Formula (II) or (II′):

in which formulae (II) and (II′):

-   -   R₇, R₈, R₉, R₁₀, R′₇, R′₈, R′₉ and R′₁₀, which are identical or        different, represent a hydrogen atom or a group chosen from:        -   alkyl;        -   alkoxy, alkylthio;        -   hydroxyl, mercapto;        -   nitro;        -   R^(o)—C(X)—X′—, R^(o)—X′—C(X)—, R^(o)—X′—C(X)—X″—, with            R^(o) representing a hydrogen atom or an alkyl or aryl            group; X, X′ and X″, which are identical or different,            representing an oxygen or sulphur atom or NR, with R            representing a hydrogen atom or an alkyl group;        -   M⁺(O)₂S(O⁻)—, with M⁺ as defined above for M⁺ or            representing a cationic counterion R₁R₂R₃R₄N⁺ as defined            above;        -   M⁺(O)CO—, with M⁺ as defined above;        -   R″—S(O)₂—, with R″ representing a hydrogen atom or an alkyl,            aryl, (di)(alkyl)amino or aryl(alkyl)amino group;            preferably, a phenylamino or phenyl group;        -   R′″—S(O)₂—X′—, with R′″ representing an alkyl group or an            aryl group which is optionally substituted, and X′ as            defined above;        -   (di)(alkyl)amino;        -   aryl(alkyl)amino, optionally substituted by one or more            groups chosen from i) nitro; ii) nitroso; iii) M⁺(O)₂S(O⁻)—            and iv) alkoxy, with M⁺ as defined above;        -   optionally substituted heteroaryl; preferably, a            benzothiazolyl group;        -   cycloalkyl; in particular cyclohexyl;        -   Ar—N═N—, with Ar representing an optionally substituted aryl            group; preferably, a phenyl optionally substituted by one or            more alkyl, M⁺(O)₂S(O⁻)— or phenylamino groups;        -   or else two contiguous groups, R₇ with R₈ or R₈ with R₉ or            R₉ with R₁₀, together form a fused benzo group A′; and R′₇            with R′₈ or R₈ with R₉, or R₁₀, with R′₁₀ together form a            fused benzo group B′; with A′ and B′ optionally substituted            by one or more groups chosen from i) nitro; ii)            nitroso; iii) M⁺(O)₂S(O⁻)—; iv) hydroxyl; v) mercapto; vi)            (di)(alkyl)amino; vii) R^(o)—C(X)—X′—; viii)            R^(o)—X′—C(X)—; ix) R^(o)—X′—C(X)—X″—; x) Ar—N═N— and xi)            aryl(alkyl)amino which is optionally substituted; with M⁺,            R^(o), X, X′, X″ and Ar as defined above;    -   W represents a sigma a bond, an oxygen or sulphur atom or a        divalent radical i) —NR—, with R as defined above, or ii)        methylene —C(R_(a))(R_(b))—, with R_(a) and R_(b), which are        identical or different, representing a hydrogen atom or an aryl        group, or else Ra and R_(b) form, together with the carbon atom        which carries them, a spirocycloalkyl; preferably, W represents        a sulphur atom or Ra and R_(b) together form a cyclohexyl;        it being understood that the formulae (II) and (II′) comprise at        least one sulphonate radical R₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate        radical R₁R₂R₃R₄N⁺(O)C(O⁻)— on one of the rings A, A′, B, B′ or        C, with R₁, R₂, R₃ and R₄ as defined above; preferably,        tetrabutylammonium sulphonate or carboxylate.

Mention may be made, as examples of dyes of formula (II), of theammonium salts derived from: Acid Red 1, Acid Red 4, Acid Red 13, AcidRed 14, Acid Red 18, Acid Red 27, Acid Red 32, Acid Red 33, Acid Red 35,Acid Red 37, Acid Red 40, Acid Red 41, Acid Red 42, Acid Red 44, AcidRed 68, Acid Red 73, Acid Red 135, Acid Red 138, Acid Red 184, Food Red1, Food Red 13, Acid Orange 6, Acid Orange 7, Acid Orange 10, AcidOrange 19, Acid Orange 20, Acid Orange 24, Acid Yellow 9, Acid Yellow36, Acid Yellow 199, Food Yellow 3, Acid Violet 7, Acid Violet 14, AcidBlue 113, Acid Blue 117, Acid Black 1, Acid Brown 4, Acid Brown 20, AcidBlack 26, Acid Black 52, Food Black 1 and Food Black 2;

and mention may be made, as examples of dyes of formula (II′), of theammonium salts derived from: Acid Red 111, Acid Red 134 and Acid Yellow38.

b) Pyrazolone Anionic Azo Dyes of Formulae (III) and (III′):

in which formulae (III) and (III′):

-   -   R₁₁, R₁₂ and R₁₁, which are identical or different, represent a        hydrogen atom, a halogen atom, an alkyl group or an M⁺(O)₂S(O⁻)—        group, with M⁺ as defined above;    -   R₁₄ represents a hydrogen atom, an alkyl group or an M⁺C(O)O⁻—        group, with M⁺ as defined above;    -   R₁₅ represents a hydrogen atom;    -   R₁₆ represents an oxo group, in which case R′₁₆ is absent, or        else R₁₅ with R₁₆ together form a double bond;    -   R₁₇ and R₁₈, which are identical or different, represent a        hydrogen atom or a group chosen from:        -   M⁺(O)₂S(O⁻)—, with M⁺ as defined above;        -   Ar—O—S(O)₂—, with Ar representing an optionally substituted            aryl group; preferably, a phenyl optionally substituted by            one or more alkyl groups;    -   R₁₉ and R₂₀, together form either a double bond or an optionally        substituted benzo group D′;    -   R′₁₆, R′₁₉, and R′₂₀, which are identical or different,        represent a hydrogen atom, an alkyl group or a hydroxyl group;    -   R₂₁ represents a hydrogen atom, an alkyl group or an alkoxy        group;    -   R_(a) and R_(b), which are identical or different, are as        defined above; preferably, R_(a) represents a hydrogen atom and        R_(b) represents an aryl group;    -   Y represents either a hydroxyl group or an oxo group;    -   represents a single bond when Y is an oxo group and represents a        double bond when Y represents a hydroxyl group;        it being understood that the formulae (III) and (III′) comprise        at least one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— on one of the        rings D or E or the formulae (III) and (III′) comprise at least        one carboxylate group R₁R₂R₃R₄N⁺(O)C(O⁻)—, with R₁, R₂, R₃ and        R₄ as defined above; preferably comprise at least one sulphonate        group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— on one of the rings D or E and more        particularly tetrabutylammonium sulphonate.

Mention may be made, as examples of dyes of formula (III), of theammonium salts derived from: Acid Red 195, Acid Yellow 23, Acid Yellow27 and Acid Yellow 76, and mention may be made, as examples of dyes offormula (III′), of the ammonium salt derived from: Acid Yellow 17.

c) Anthraquinone Dyes of Formulae (IV) and (IV′):

in which formulae (IV) and (IV):

-   -   R₂₂, R₂₃, R₂₄, R₂₅, R₂₆ and R₂₇, which are identical or        different, represent a hydrogen atom, a halogen atom or a group        chosen from:        -   alkyl;        -   hydroxyl, mercapto;        -   alkoxy, alkylthio;        -   optionally substituted aryloxy or arylthio, preferably            substituted by one or more groups chosen from alkyl and            M⁺(O)₂S(O⁻)—, with M⁺ as defined above;        -   aryl(alkyl)amino optionally substituted by one or more            groups chosen from alkyl and M⁺(O)₂S(O⁻)—, with M⁺ as            defined above;        -   (di)(alkyl)amino;        -   (di)(hydroxyalkyl)amino;        -   M⁺(O)₂S(O⁻)—, with M⁺ as defined above;    -   Z′ represents a hydrogen atom or an NR₂₈R₂₉ group with R₂₈ and        R₂₉, which are identical or different, representing a hydrogen        atom or a group chosen from:        -   alkyl;        -   (poly)hydroxyalkyl, such as hydroxyethyl;        -   aryl optionally substituted by one or more groups,            particularly i) alkyl, such as methyl, n-dodecyl or            n-butyl; ii) M⁺(O)₂S(O⁻)—, with M⁺ as defined above; iii)            R^(o)—C(X)—X′—, R^(o)—X′—C(X)— or R^(o)—X′—C(X)—X″—, with            R^(o), X, X′ and X″ as defined above; preferably, R^(o)            represents an alkyl group;        -   cycloalkyl; in particular cyclohexyl;    -   Z represents a group chosen from hydroxyl and NR′₂₈R′₂₉ with        R′₂₈ and R′₂₉, which are identical or different, representing        the same atoms or groups as R₂ and R₂₉ as defined above;        it being understood that the formulae (IV) and (IV′) comprise at        least one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)—, with R₁, R₂, R₃        and R₄ as defined above; preferably, tetrabutylammonium        sulphonate.

d) Nitro Dyes of Formulae (V) and (V′):

in which formulae (V) and (V′):

-   -   R₃₀, R₃₁ and R₃₂, which are identical or different, represent a        hydrogen atom, a halogen atom or a group chosen from:        -   alkyl;        -   alkoxy optionally substituted by one or more hydroxyl            groups, or alkylthio optionally substituted by one or more            hydroxyl groups;        -   hydroxyl, mercapto;        -   nitro, nitroso;        -   (poly)haloalkyl;    -   R^(o)—C(X)—X′—, R^(o)—X′—C(X)—, R^(o)—X′—C(X)—X″—, with R^(o),        X, X′ and X″ as defined above;        -   M⁺(O)₂S(O⁻)—, with M⁺ as defined above;        -   M⁺ (O)CO⁻—, with M⁺ as defined above;        -   (di)(alkyl)amino;        -   (di)(hydroxyalkyl)amino;        -   heterocycloalkyl, such as piperidino, piperazino or            morpholino;    -   in particular, R₃₀, R₃₁ and R₃₂ represent a hydrogen atom;    -   R_(c) and R_(d), which are identical or different, represent a        hydrogen atom or an alkyl group;    -   W is as defined above; W represents in particular an —NH— group;    -   ALK represents a linear or branched divalent C₁-C₆ alkylene        group, in particular, ALK represents a —CH₂CH₂ group;    -   n has a value of 1 or 2;    -   p represents an integer between 1 and 5 inclusive;    -   q represents an integer between 1 and 4 inclusive;    -   u has a value of 0 or 1;    -   when n has a value of 1, J represents a nitro or nitroso group,        in particular a nitro group;    -   when n has a value of 2, J represents an oxygen or sulphur atom        or a divalent —S(O)_(m)— radical with m representing an integer        which is 1 or 2; preferably, J represents an —SO₂— radical;    -   M′ is as defined above for M⁺;

which is present or absent, represents a benzo group optionallysubstituted by one or more R₃₀ groups as defined above; it beingunderstood that the formulae (V) and (V′) comprise at least onesulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate groupR₁R₂R₃R₄N⁺(O)C(O⁻)—, with R₁, R₂, R₃ and R₄ as defined above; preferablytetrabutylammonium sulphonate or carboxylate.

Mention may be made, as examples of dyes of formula (V), of the ammoniumsalts derived from: Acid Brown 13 and Acid Orange 3; mention may bemade, as examples of dyes of formula (V′), of: Acid Yellow 1, sodiumsalt of 2,4-dinitro-1-naphthol-7-sulphonic acid,2-pipendino-5-nitrobenzenesulphonic acid,2-(4′-N,N(2″-hydroxyethyl)amino-2′-nitro)anilineethanesulphonic acid and4-(J3-hydroxyethylamino)-3-nitrobenzenesulphonic acid.

d) Triarylmethane Dyes of Formula (VI):

in which formula (VI):

-   -   R₃₃, R₃₄, R₃₅ and R₃₆, which are identical or different,        represent a hydrogen atom or a group chosen from alkyl,        optionally substituted aryl and optionally substituted        arylalkyl, in particular an alkyl group and a benzyl group        optionally substituted by an M⁺(O)_(m)S(O⁻)— group, with M⁺ and        m as defined above;    -   R₃₇, R₃₈, R₃₉, R₄₀, R₄₁, R₄₂, R₄₃ and R₄₄, which are identical        or different, represent a hydrogen atom or a group chosen from:        -   alkyl;        -   alkoxy, alkylthio;        -   (di)(alkyl)amino;        -   hydroxyl, mercapto;        -   nitro, nitroso;        -   R^(o)—C(X)—X′—, R^(o)—X′—C(X)—, R^(o)—X′—C(X)—X″—, with            R^(o) representing a hydrogen atom or an alkyl or aryl group            and X, X′ and X″, which are identical or different,            representing an oxygen or sulphur atom or an NR group with R            representing a hydrogen atom or an alkyl group;        -   M⁺(O)₂S(O⁻)—, with M⁺ representing a hydrogen atom or a            cationic counterion;        -   M⁺(O)CO—, with M⁺ as defined above;        -   or else two contiguous groups, R₄₁ with R₄₂ or R₄₂ with R₄₃            or R₄₃ with R₄₄, together form a fused benzo group: I′; with            I′ optionally substituted by one or more groups chosen            from i) nitro; ii) nitroso; iii) M⁺(O)₂S(O⁻)—; iv)            hydroxyl; v) mercapto; vi) (di)(alkyl)amino; vii)            R^(o)—C(X)—X′—; viii) R^(o)—X′—C(X)—; ix) R^(o)—X′—C(X)—X″—;            with M⁺, R^(o), X, X′, X″ as defined above; in particular,            R₃₇ to R₄₀ represent a hydrogen atom and R₄₁ to R₄₄, which            are identical or different, represent a hydroxyl or            M⁺(O)₂S(O⁻)— group; and, when R₄₃ with R₄₄ together form a            benzo group, it is preferably substituted by an (O)₂S(O⁻)—            group;            it being understood that at least one of the rings G, H, I            or I′ comprises at least one sulphonate group            R₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate group            R₁R₂R₃R₄N⁺(O)C(O⁻)—; preferably tetrabutylammonium            sulphonate or carboxylate;

Mention may be made, as examples of dyes of formula (VI), of theammonium salts derived from: Acid Blue 1, Acid Blue 3, Acid Blue 7, AcidBlue 9, Acid Violet 49 and Acid Green 50.

e) Xanthene-Derived Dyes of Formula (VII):

in which formula (VII):

-   -   R₄₅, R₄₆, R₄₇ and R₄₈, which are identical or different,        represent a hydrogen atom or a halogen atom;    -   R₄₉, R₅₀, R₅₁ and R₅₂, which are identical or different,        represent a hydrogen atom, a halogen atom or a group chosen        from:        -   alkyl;        -   alkoxy, alkylthio;        -   hydroxyl, mercapto;        -   nitro, nitroso;        -   M⁺(O)₂S(O⁻)—, with M⁺ representing a hydrogen atom or a            cationic counterion;        -   M⁺(O)CO⁻—, with M⁺ as defined above;

in particular R₅₃, R₅₄, R₅₅ and R₄₈ represent a hydrogen atom or ahalogen atom;

-   -   G represents an oxygen or a sulphur atom or an NR_(e) group,        with R_(e) as defined above; in particular, G represents an        oxygen atom;    -   L represents an alkoxide M⁺O—; a thioalkoxide M⁺S⁻ or an NR_(f)        group, with R_(f) representing a hydrogen atom or an alkyl group        and M⁺ as defined above; M⁺ is in particular sodium, potassium        or R₁R₂R₃R₄N⁺;    -   L′ represents an oxygen or sulphur atom or an ammonium group:        N⁺R_(f)R_(g), with R_(f) and R_(g), which are identical or        different, representing a hydrogen atom, an alkyl group or an        aryl group which is optionally substituted; L′ represents in        particular an oxygen atom or a phenylamino group optionally        substituted by one or more alkyl or M⁺(O)_(m)S(O⁻)— groups, with        m and M⁺ as defined above;    -   Q and Q′, which are identical or different, represent an oxygen        or sulphur atom; in particular, Q and Q′ represent an oxygen        atom;    -   M⁺ is as defined above;        it being understood that the formula (VII) comprises at least        one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate group        R₁R₂R₃R₄N⁺(O)C(O⁻)—, with R₁, R₂, R₃ and R₄ as defined above;        preferably tetrabutylammonium sulphonate or carboxylate.

Mention may be made, as examples of dyes of formula (VII), of theammonium salts derived from: Acid Yellow 73, Acid Red 51, Acid Red 87,Acid Red 92, Acid Red 95 and Acid Violet 9.

f) Indole-Derived Dyes of Formula (VIII):

in which formula (VIII):

-   -   R₅₃, R₅₄, R₅₅, R₅₆, R₅₇, R₅₈, R₅₉ and R₆₀, which are identical        or different, represent a hydrogen atom or a group chosen from:        -   alkyl;        -   alkoxy, alkylthio;        -   hydroxyl, mercapto;        -   nitro, nitroso;        -   R—C(X)—X′—, R^(o)—X′—C(X)—, R^(o)—X′—C(X)—X″—, with R^(o)            representing a hydrogen atom or an alkyl or aryl group and            X, X′ and X″, which are identical or different, representing            an oxygen or sulphur atom or an NR group, with R            representing a hydrogen atom or an alkyl group;        -   M⁺(O)₂S(O⁻)—, with M⁺ as defined above;        -   M⁺(O)CO—, with M⁺ as defined above;    -   G represents an oxygen or sulphur atom or an NR_(e) group, with        R_(e) as defined above; in particular, G represents an oxygen        atom;    -   R_(i) and R_(h), which are identical or different, represent a        hydrogen atom or an alkyl group;        it being understood that the formula (VIII) comprises at least        one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate group        R₁R₂R₃R₄N⁺(O)C(O⁻)—, with R₁, R₂, R₃ and R₄ as defined above;        preferably tetrabutylammonium sulphonate or carboxylate.

Mention may be made, as example of dyes of formula (VIII), of theammonium salt derived from: Acid Blue 74.

g) Quinoline-Derived Dyes of Formula (IX):

in which formula (IX):

-   -   R₆₁ represents a hydrogen or halogen atom or an alkyl group;    -   R₆₂, R₆₃, and R₆₄, which are identical or different, represent a        hydrogen atom or an M⁺(O)₂S(O⁻)— group, with M⁺ as defined        above;    -   or else R₆₁ with R₆₂ or R₆₁ with R₆₄ together form a benzo group        optionally substituted by one or more M⁺(O)₂S(O⁻)— groups, with        M⁺ representing a hydrogen atom or a cationic counterion;        it being understood that the formula (IX) comprises at least one        sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)—, with R₁, R₂, R₃ and R₄ as        defined above; preferably tetrabutylammonium sulphonate.

Mention may be made, as examples of dyes of formula (IX), of theammonium salts derived from: Acid Yellow 2, Acid Yellow 3 and AcidYellow 5.

More particularly, the dyes of formulae (UI) to (VII) of use in theinvention are chosen from the ammonium salts derived from:

(C.I. 45380) Acid Red 87 (VII) (C.I. 10316)2,4-dinitro-1-naphthol-7-sulphonic acid (V′) (C.I. 10383) Acid Orange 3(V) (C.I. 13015) Acid Yellow 9/Food Yellow 2 (II) (C.I. 14780) DirectRed 45/Food Red 13 (II) (C.I. 13711) Acid Black 52 (II) (C.I. 13065)Acid Yellow 36 (II) (C.I. 14700)1-hydroxy-2-(5′-sulphonato-2′,4′-xylylazo)naphthalene- 4-sulphonicacid/Food Red 1(II) (C.I. 14720) Acid Red 14/Food Red 3/Mordant Blue 79(II) (C.I. 14805) 4-hydroxy-3-[(2-methoxy-5-nitrophenyl)diaza]-6-(phenylamino)naphthalene-2-sulphonic acid/Acid Brown 4 (II) (C.I. 15510)Acid Orange 7/Pigment Orange 17/Solvent Orange 49 (II) (C.I. 15985) FoodYellow 3/Pigment Yellow 104 (II) (C.I. 16185) Acid Red 27/Food Red 9(II) (C.I. 16230) Acid Orange 10/Food Orange 4 (II) (C.I. 16250) AcidRed 44 (II) (C.I. 17200) Acid Red 33/Food Red 12 (II) (C.I. 15685) AcidRed 184 (II) (C.I. 19125) Acid Violet 3 (II) (C.I. 18055)1-hydroxy-2-(4′-acetamidophenylazo)-8-acetamidonaphthalene-3,6-disulphonic acid/ Acid Violet 7/Food Red 11(II)(C.I. 18130) Acid Red 135 (II) (C.I. 19130) Acid Yellow 27(III) (C.I.19140) Acid Yellow 23/Food Yellow 4 (III) (C.I. 20170)1,3-dihydroxy-2-(2″,4″-dimethylphenylazo)-6-(4′-sulphonatophenylazo)-benzene/Acid Orange 24 (II) (C.I. 20470)1-amino-2-(4′-nitrophenylazo)-7-phenylazo-8-hydroxynaphthalene-3,6-disulphonic acid/Acid Black 1 (II) (C.I. 23266)4′-(4-((4-methylphenyl)sulphonyloxy)phenylazo)-2,2″-dimethyl-4-(1-hydroxy-3,6-disulphonato-2-naphthylazo) biphenyl/Acid Red111 (II′) (C.I. 27755) Food Black 2 (II) (C.I. 28440)1-(4′-sulphonatophenylazo)-4-(8-acetylamino-1-hydroxy-3,5-disulphonato-2-naphthylazo)-6-sulphonatonaphthalene (tetrasodiumsalt)/Food Black 1 (II) (C.I. 42090) Acid Blue 9 (VI) (C.I. 60730) AcidViolet 43 (IV) (C.I. 61570) Acid Green 25 (IV) (C.I. 62045)1-amino-4-cyclohexylamino-9,10-anthraquinone-2- sulphonic acid/Acid Blue62 (IV) (C.I. 62105) Acid Blue 78 (IV) (C.I. 14710)4-hydroxy-3-((2-methoxyphenyl)azo)-1- naphthalenesulphonic acid/Acid Red4 (II) 2-piperidino-5-nitrobenzenesulphonic acid (V′)2-(4′-N,N(2″-hydroxyethyl)amino-2′-nitro) anilineethanesulphonic acid(V′) 4-(β-hydroxyethylamino)-3-nitrobenzenesulphonic acid (V′) (C.I.42640) Acid Violet 49 (VI) (C.I. 42080) Acid Blue 7 (VI) (C.I. 58005)1,2-dihydroxy-3-sulphoanthraquinone/Mordant Red 3 (IV) (C.I. 62055)1-amino-9,10-dihydro-9,10-dioxo-4-(phenylamino)-2- anthracenesulphonicacid/Acid Blue 25 (IV) (C.I. 14710)4-hydroxy-3-((2-methoxyphenyl)azo)-1- naphthalenesulphonic acid/Acid Red4 (II)

The majority of these dyes are described in particular in the ColorIndex published by The Society of Dyers and Colorists, P.O. Box 244,Perkin House, 82 Grattan Road, Bradford, Yorkshire, BD1 2JBN, England.

The anionic dyes according to the invention can be obtained by exchangesof cationic counterion with one or more ammoniums of R₁R₂R₃R₄N⁺ type,with R₁, R₂, R₃ and R₄ as defined above.

The more particularly preferred anionic dyes for which the cationiccounterions can be replaced are the dyes denoted in the Color Indexunder the code C.I. 58005 (monosodium salt of1,2-dihydroxy-9,10-anthraquinone-3-sulphonic acid), C.I. 60730(monosodium salt of2-[(9,10-dihydro-4-hydroxy-9,10-dioxo-1-anthracenyl)amino]-5-methylbenzenesulphonicacid), C.I. 15510 (monosodium salt of4-[(2-hydroxy-1-naphthyl)azo]benzenesulphonic acid), C.I. 15985(disodium salt of6-hydroxy-5-[(4-sulphophenyl)azo]-2-naphthalenesulphonic acid), C.I.17200 (disodium salt of5-amino-4-hydroxy-3-phenylazo-2,7-naphthalenedisulphonic acid), C.I.20470 (disodium salt of1-amino-2-(4′-nitrophenylazo)-7-phenylazo-8-hydroxy-3,6-naphthalenedisulphonicacid), C.I. 42090 (disodium salt ofN-ethyl-N-[4-[[4-[ethyl[(3-sulphophenyl)methyl]amino]phenyl](2-sulphophenyl)methylene]-2,5-cyclohexadien-1-ylidene]-3-sulphobenzenemethanaminiumhydroxide, internal salt) and C.I.61570 (disodium salt of2,2′-[(9,10-dihydro-9,10-dioxo-1,4-anthracenediyl)diimino]bis[5-methylbenzenesulphonicacid].

Use may also be made of compounds corresponding to the mesomeric ortautomeric forms of the structures (II) to (IX).

More preferably, the anionic dyes of formula (I) according to theinvention are chosen from those of formulae (II), (III) and (IV).

According to a specific embodiment of the invention, the dyes are chosenfrom (IIa), (Ilia) and (IVa) below:

in which formula (IIa):

-   -   R₇, R₈, R₉, R₁₀, R′₇, R′₈, R′₉ and R′₁₀, which are identical or        different, represent a hydrogen atom or a group chosen from:        -   hydroxyl;        -   nitro, nitroso;        -   (di)(alkyl)amino;        -   M⁺(O)₂S(O⁻)—, with M⁺ representing a hydrogen atom, a            cationic counterion or R₁R₂R₃R₄N⁺ as defined above; and        -   Ar—N═N— with Ar representing an optionally substituted aryl            group; preferably a phenyl optionally substituted by one or            more alkyl or M⁺(O)₂S(O⁻)— groups;        -   or else two contiguous groups R₇ with R₈ or R₈ with R₉ or R₉            with R₁₀ together form a fused benzo group A′; and R′₇ with            R′₈ or R′₈ with R′₉ or R′₉ with R′₁₀ together form a fused            benzo group B′; with A′ and B′ optionally substituted by one            or more groups chosen from a) M⁺(O)₂S(O⁻)—; b) hydroxyl; c)            Ar—N═N—; with M⁺ and Ar as defined above;            it being understood that the formula (IIa) comprises at            least one sulphonate radical R₁R₂R₃R₄N⁺(O)₂S(O⁻)— on one of            the rings A, A′, B, B′, with R₁, R₂, R₃ and R₄ as defined            above; preferably tetrabutylammonium sulphonate;

in which formula (Ilia):

-   -   R₁₁, R₁₂ and R₁₃, which are identical or different, represent a        hydrogen or halogen atom or an alkyl or M⁺(O)₂S(O⁻)— group, with        M⁺ as defined above;    -   R₁₄ represents a hydrogen atom, an alkyl group or an M⁺C(O⁻)O—        group, with M⁺ as defined above;    -   R₁₆, R₁₇, R₁₈, R₁₉, and R₂₀, which are identical or different,        represent a hydrogen atom or an alkyl, hydroxyl or M⁺(O)₂S(O⁻)—        group, with M⁺ as defined above;    -   Y represents either a hydroxyl group or an oxo group;    -   represents a single bond when Y is an oxo group and represents a        double bond when Y represents a hydroxyl group;        it being understood that the formula (IIIa) comprises at least        one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— on one of the rings D        or E or carboxylate group R₁R₂R₃R₄N⁺(O)C(O⁻)—, with R₁, R₂, R₃        and R₄ as defined above; preferably tetrabutylammonium        sulphonate;

in which formula (IVa):

-   -   Z′ represents an NR₂₈R₂₉ group, with R₂₈ representing a hydrogen        atom or an alkyl group and R₂₉ representing an aryl group which        is optionally substituted, in particular by one or more groups        chosen from i) alkyl, such as methyl, and ii) M⁺(O)₂S(O⁻)—, with        M⁺ as defined above;    -   Z represents a group chosen from hydroxyl and NR′₂₈R′₂₉, with        R′₂₈ and R′₂₉, which are identical or different, representing        the same atoms or groups as R₂₈ and R₂₉ as defined above;        it being understood that the formula (IVa) comprises at least        one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)—, with R₁, R₂, R₃ and        R₄ as defined above; preferably tetrabutylammonium sulphonate.

Mention may be made, by way of examples, of the following anionic dyes:

Anionic part “resulting” from commercial dye Corresponding structureAcid orange 7

Acid black 1

Acid red 18

Acid yellow 23

Acid violet 43

with M⁺, which are identical or different, as defined above, it beingunderstood that at least one of the cationic counterions represents acationic counterion R₁R₂R₃R₄N⁺ as defined above; in particular, M⁺ areidentical and represent a tetrabutylammonium (CH₃—CH₂—CH₂—CH₂)₄N⁺.

The dyes of formula (I) are derived from anionic dyes which are eithercommercially available or are accessible by syntheses employingconventional synthetic techniques known to a person skilled in the art.The “known” dyes comprise a cationic counterion, generally an inorganiccounterion (alkali metal or alkaline earth metal cation), which isreplaced by an organic ammonium counterion R₁R₂R₃R₄N⁺ as defined above.This substitution of cationic counterions can be carried out by aconventional ion-exchange method, for example with an ion-exchange resinor with an ion-exchange column (ion exchange methodology, see forexample,http://www.sigmaalddch.com/analytical-chromatography/sample-preparation/spe/ionexchange-methodology.htmland “Ion Exchange Material—Properties and Applications”, Andrei. A.Zagorodni, 1st Ed., 2007, Oxford, Elsevier BV; “Ion Exchange”, H.Friedrich G, 1995, NY: MacGraw-Hill, chapt. 2.3, p. 12: Ion ExchangeResins, chapt. 3, p. 29: Cation Exchangers; chapt. 9, p. 421: IonExchange Column; Ullmann's Encyclopedia of Industrial Chemistry, “IonExchange” F. Dardel and Thomas V. Arden, Published Online: Apr. 15,2008, DOI: 10.1002/14356007.a14_(—)393.pub2; Kirk-Othmer Encyclopedia ofChemical Technology, “Ion Exchange” C. Dickert, Published Online: Apr.12, 2000, DOI: 10.1002/0471238961.09151404090311.a01).

Another method consists in dissolving the known anionic dye in awater-immiscible organic solvent, such as halogenated organic solvents,for example dichloromethane, chloroform or methyl tetrachloride, oraromatic organic solvents, such as toluene or tetrahydrofuran (THF), andin adding thereto an aqueous solution comprising tetralkylammoniumsalts, such as tetraalkylammonium hydrogensulphate R₁R₂R₃R₄N⁺HO—S(O)₂O⁻or tetraalkylammonium carboxylates R₁R₂R₃R₄N⁺R—C(O)O⁻, with Rrepresenting a hydrogen atom or a (C₁-C₆)alkyl group and R₁R₂R₃R₄N⁺being as defined above.

Depending on the amount of tetraalkylammonium salt added to the aqueoussolution and on the number of sulphonate or carboxylate anionicgroup(s), it is possible to replace one or more cationic counterions.If, for example, all of the cationic counterions have to be replaced,then the choice is made to employ an aqueous solution saturated withtetraalkylammonium salt. The resulting mixture (aqueoussolution+tetraalkylammonium salt+organic solvent+“known” anionic dye) issubsequently left at ambient temperature with stirring for between 1minute and one week, such as from minutes to 48 hours, particularly oneday and preferably between 2 and 4 hours. The organic phase issubsequently separated from the aqueous phase (by settling) and thenoptionally washed and separated again (by settling). The organic phaseis optionally dried using a conventional dehydrating agent, such asalkali metal or alkaline earth metal sulphates, such as sodium sulphate,and then filtered. The starting organic solvent is subsequentlyevaporated, for example using a rotary evaporator of ROTAVAPOR® type.

II. Composition Comprising at Least One Anionic Dye of Formula (I)

Another subject-matter of the invention is a composition comprising, ina cosmetic medium, at least one anionic dye of formula (I) as definedabove.

According to a particularly advantageous form of the invention, thecosmetic composition comprising one or more dyes of formula (I) does notcomprise a chemical oxidizing agent.

The term “chemical oxidizing agent” is understood to mean any chemicalor enzymatic oxidizing agent other than atmospheric oxygen.

The dyeing composition of use in the invention generally comprises anamount of anionic dye of formula (I) of between 0.001 and 50%, withrespect to the total weight of the composition. Preferably, this amountis between 0.005 and 20% by weight and more preferably still between0.01 and 5% by weight, with respect to the total weight of thecomposition.

The dyeing composition can moreover comprise additional direct dyesother than those of formula (I). These direct dyes are, for example,chosen from neutral, anionic or cationic nitrobenzene direct dyes,neutral, anionic or cationic azo direct dyes, tetraazapentamethine dyes,neutral, anionic or cationic quinone and in particular anthraquinonedyes, azine direct dyes, triarylmethane direct dyes, indoamine directdyes and natural direct dyes.

Mention may be made, among natural direct dyes, of lawsone, juglone,alizarin, purpurin, carminic acid, kermesic acid, purpurogallin,protocatechualdehyde, indigo, isatin, curcumin, spinulosin orapigenidine. It is also possible to use extracts or decoctionscomprising these natural dyes and in particular cataplasms orhenna-based extracts.

The dyeing composition can comprise one or more oxidation bases and/orone or more couplers conventionally used for the dyeing of keratinousfibres.

Mention may be made, among oxidation bases, of para-phenylenediamines,bisphenylalkylenediamines, para-aminophenols, bis-para-aminophenois,ortho-aminophenols, heterocyclic bases and their addition salts.

Mention may in particular be made, among these couplers, ofmeta-phenylenediamines, meta-aminophenois, meta-diphenols, naphthalenecouplers, heterocyclic couplers and their addition salts.

The coupler or couplers are each generally present in an amount ofbetween 0.001 and 10% by weight of the total weight of the dyeingcomposition, preferably between 0.005 and 6% by weight.

The oxidation base or bases present in the dyeing composition aregenerally present each in an amount of between 0.001 and 10% by weightof the total weight of the dyeing composition, preferably between 0.005and 6% by weight.

Generally, the addition salts of the oxidation bases and couplers whichcan be used in the context of the invention are chosen in particularfrom the addition salts with an acid, such as hydrochlorides,hydrobromides, sulphates, citrates, succinates, tartrates, lactates,tosylates, benzenesulphonates, phosphates and acetates, and the additionsalts with a base, such as alkali metal hydroxides, for example sodiumhydroxide or potassium hydroxide, ammonia, amines or alkanolamines.

The medium appropriate for the dyeing, also known as dyeing vehicle, isa cosmetic medium generally composed of water or of a mixture of waterand of at least one organic solvent. Mention may be made, as organicsolvent, for example, of lower C₁-C₄ alkanols, such as ethanol andisopropanol, polyols and polyol ethers, such as 2-butoxyethanol,propylene glycol, propylene glycol monomethyl ether, diethylene glycolmonoethyl ether and diethylene glycol monomethyl ether, aromaticalcohols, such as benzyl alcohol or phenoxyethanol, and their mixtures.

The solvents, when they are present, are preferably present inproportions preferably of between 1 and 99% by weight approximately,with respect to the total weight of the dyeing composition, morepreferably still between 5 and 95% by weight approximately.

The dyeing composition can also include various adjuvants conventionallyused in hair-dyeing compositions, such as anionic, cationic, nonionic,amphoteric or zwitterionic surface-active agents or their mixtures,anionic, cationic, nonionic, amphoteric or zwitterionic polymers ortheir mixtures, inorganic or organic thickening agents, in particularanionic, cationic, nonionic and amphoteric polymeric associativethickeners, antioxidants, penetrating agents, sequestering agents,fragrances, buffers, dispersing agents, conditioning agents, such as,for example, volatile or non-volatile and modified or unmodifiedsilicones, such as aminated silicones, film-forming agents, ceramides,preservatives, opacifying agents or conducting polymers.

The above adjuvants are generally present in an amount of, for each ofthem, between 0.01 and 20% by weight, with respect to the weight of thecomposition.

Of course, a person skilled in the art will take care to choose this orthese optional additional compounds so that the advantageous propertiesintrinsically attached to the dyeing composition in accordance with theinvention are not, or not substantially, detrimentally affected by theenvisaged addition or additions.

The pH of the dyeing composition is generally between 3 and 14approximately, preferably between 4 and 11 approximately and moreparticularly between 5 and 10. It can be adjusted to the desired valueusing acidifying or basifying agents commonly used in dyeing keratinousfibres or else using conventional buffer systems.

Mention may be made, among acidifying agents, by way of example, ofinorganic or organic acids, such as: i) hydrochloric acid HCl, ii)hydrobromic acid HBr, iii) sulphuric acid H₂SO₄, iv) alkanesulphonicacids: Alk-S(O)₂OH, such as methanesulphonic acid and ethanesulphonicacid; v) arenesulphonic acids: Ar—S(O)₂OH, such as benzenesulphonic acidand toluenesulphonic acid; yl) citric acid; vii) succinic acid; viii)tartaric acid; ix) lactic acid; x) alkoxysulphinic acids: Alk-O—S(O)OH,such as methoxysulphinic acid and ethoxysulphinic acid; xi)aryloxysulphinic acids, such as tolyloxysulphinic acid andphenoxysulphinic acid; xii) phosphoric acid H₃PO₄; xiii) acetic acidCH₃COOH; xiv) triflic acid CF₃SO₃H; and xv) tetrafluoroboric acid HBF₄,more particularly hydrochloric acid, orthophosphoric acid, sulphuricacid, carboxylic acids, such as acetic acid, tartaric acid, citric acidor lactic acid, or sulphonic acids.

Mention may be made, among basifying agents, of inorganic or organicbases, more particularly ammonia, alkaline carbonates, alkanolamines,such as mono-, di- and triethanolamines and their derivatives, sodiumhydroxide, potassium hydroxide and the compounds of following formula(7):

in which formula (y):

-   -   W_(a) is a (C₁-C₁₀)alkylene radical optionally substituted by a        hydroxyl group or a C₁-C₄ alkyl radical and/or optionally        substituted by one or more heteroatoms, such as O or N,        preferably, W is a propylene;    -   R_(a1), R_(a2), R_(a3) and R_(a4), which are identical or        different, represent a hydrogen atom, a C₁-C₄ alkyl radical or a        C₁-C₄ hydroxyalkyl radical.

The dyeing composition can be provided in various forms, such as in theform of a liquid, cream or gel or in any other form appropriate forcarrying out dyeing of keratinous fibres and in particular of the hair.

III. Dyeing Method Starting from Anionic Dye of Formula (I)

Another subject-matter of the invention is a method for dyeingkeratinous fibres which consists in applying, to the said fibres, acomposition comprising at least one anionic dye of formula (I) asdefined above.

The dyeing method according to the invention can also make it possibleto optically lighten keratinous fibres, in particular dark keratinousfibres, such as keratinous fibres with a height of tone of less than orequal to 6 and in particular of less than or equal to 4, by employing acomposition comprising at least one fluorescent anionic dye of formula(I), which are preferably dyes in the range of the orangey colours.Mention may be made in particular of xanthene-derived fluorescent dyes(VII) as defined above, in particular the ammonium derivatives of: AcidYellow 73, Acid Red 51, Acid Red 87 and Acid Red 92. According to aparticularly advantageous embodiment of the invention, the dyeing oroptical lightening method does not involve any chemical oxidizing agent.

According to an alternative form of the dyeing method, once thecomposition comprising at least one anionic dye of formula (I) isapplied to the keratinous fibres, the composition is left for a certainperiod of time and then the keratinous fibres are rinsed and/orsuperficially dried and then dried in air or with a hairdryer.

The duration of the treatment after application of the compositioncomprising at least one dye of formula (I) can be short, for examplefrom 0.1 second to 1 hour, particularly between 5 minutes and 50 minutesand more particularly between minutes and 45 minutes, and the leave-intime is preferably 30 minutes.

The examples which follow serve to illustrate the invention without,however, exhibiting a limiting nature.

The anionic dyes of the examples below were fully characterized byconventional spectroscopic and spectrometric methods.

PREPARATION EXAMPLE General Preparation of the Dyes of the Invention:Counterion Exchange

A “known” anionic dye comprising the sodium counterion is suspended indichloromethane. The water saturated with tetrabutylammoniumhydrogensulphate is then added (equivalent volume) and then the mixtureis stirred at ambient temperature for 3 hours. The organic phase isrecovered and then washed several times with distilled water in order toremove the traces of starting dye. The organic phase is subsequentlydried with sodium sulphate, filtered and then evaporated to dryness.Powders are obtained. The analyses are in accordance with the expectedstructures. The dyes synthesized are given below:

Structure of the dye obtained according to the Starting “known” dyeinvention

Preparation of Dye

A mixture of C.I. Acid Orange 7 (17.5 g, 50 mmol), of tetrabutylammoniumchloride (16.7 g, 60 mmol), of dichloromethane (200 ml) and of water(150 ml) is stirred for 2 h. The aqueous phase is recovered and washedtwice with dichloromethane (2×200 ml) and then the three dichloromethanealiquots are combined, washed with water (3×200 ml) and then evaporatedto dryness. An orange powder (23.1 g) is obtained. M.p.: 156-158° C.

DYEING EXAMPLE Example 1 Dyeing Method

Structure of the dye C.I. Acid Orange 7 (comparative)

Dye 1 (invention)

Two dyeing compositions were prepared according to the table below: acomposition (A) comprising C.I. Acid Orange 7 (comparative) and acomposition (B) comprising the dye 1 (invention):

Compositions (A), comparative (B), invention Benzoic acid 0.5 g 0.5 gEthanol 15 g 15 g Benzyl alcohol 5 g 5 g C.I. Acid Orange 7 1 × 10⁻⁴ mol— (comparative) Dye 1 (invention) — 1 × 10⁻⁴ mol Water q.s. for 100 gq.s. for 100 gTwo locks weighing 1 g of hair (90% natural white hairs) originatingfrom the same lock batch are subsequently steeped in 5 g of each dyeingcomposition (1 lock in the composition (A) and the other lock in thecomposition (B)). The locks are maintained in (A) and (B) at ambienttemperature for 30 minutes. They are subsequently rinsed with water,shampooed once and then dried in air.

Results:

On conclusion of the dyeing, the colour of the locks is measured with aMinolta CM2600d spectrocolorimeter (specular components included, angle10°, illuminant D65) in the C.I.E L*a*b* system. In this system, L*represents the intensity of the colour, a* indicates the green/redcolour axis and b* indicates the blue/yellow colour axis.

-   -   ΔE represents the variation in colour between an “uncoloured”        lock of hair and a coloured lock of hair and is determined from        the following formula:

ΔE=√{square root over ((L*−L ₀*)²+(a*−a _(o)*)²+(b*−b _(o)*)²)}{squareroot over ((L*−L ₀*)²+(a*−a _(o)*)²+(b*−b _(o)*)²)}{square root over((L*−L ₀*)²+(a*−a _(o)*)²+(b*−b _(o)*)²)}

in which L*, a* and b* represent the values measured on the colouredlock and L₀*, a₀* and b₀* represent the values measured on theuncoloured lock.The higher the value of ΔE, the more coloured is the lock.

-   -   C* represents the chromaticity in the C.I.E L*, a*, b* system,        which is calculated according to the following equation:

C*=√{square root over (a* ² +b*)}

in which a* and b* are as defined above. The higher the value of C*, thegreater the chromaticity of the colour.The colorimetric results obtained are given in the tables below.

L*(D65) *(D65) b*(D65) Hairs (90% natural white hairs) 54.25 1.64 11.08Composition A (comparative) 50.15 10.77 18.78 Composition B (invention)42.4 26.91 35.74

C* ΔE measured Composition A (comparative) 21.65 10.4 Composition B(invention) 44.74 27.5It is apparent, from the above tables, that the colouring power of thedyes according to the invention is significantly greater than that ofthe comparative:

-   -   The variation in colour of the hair obtained before and after        dyeing is significantly greater with the composition B, which        comprises the dye 1 according to the invention, than that        obtained with the comparative composition, which comprises the        “known” anionic dye C.I. Acid Orange 7 (ΔE=27.5 vs 10.4).    -   The value of L* measured is in addition significantly lower for        the colour of the hair obtained after treatment with the        composition B than that obtained with the comparative        composition (L=42.4 vs. 50.15). The colour of the hair thus        appears visually much darker and consequently more powerful and        more intense with the composition B according to the invention.    -   The colour obtained with the composition B according to the        invention is significantly more chromatic than that obtained        with the comparative composition (C*=44.74 vs. 21.65).

1-18. (canceled)
 19. A method for dyeing keratinous fibers, said methodcomprising applying to the fibers a composition comprising at least oneanionic dye of formula (I):

and optical isomers, geometric isomers, and solvates thereof, wherein informula (I): R₁, R₂, R₃ and R₄, which are identical or different, arechosen from i) (C₁-C₂₀)alkyls; and ii) (C₂-C₂₀)alkenyls; it beingpossible for the alkyl or alkenyl group of the groups of i) and ii) tobe interrupted by at least one identical or different heteroatoms chosenfrom oxygen, sulphur, and N(Rα), wherein Rα is chosen from hydrogenatoms and alkyl groups; Col⁽⁻⁾ _(m) represents the anionic part of theanionic dye comprising at least one sulphonate group and/or at least onecarboxylate group, and wherein m is the anionic charge; wherein m and n,which are identical or different, represent an integer ranging from 1 to10; wherein: when the anionic part of the anionic dye comprises asulphonate group or a carboxylate group, then m=n=1; and when theanionic part of the anionic dye comprises anionic groups other than asulphonate or carboxylate group, the anionic part is combined with atleast one cationic counterion, organic, inorganic or R₁R₂R₃R₄N⁺, makingit possible to achieve electrical neutrality of the formula (I).
 20. Themethod according to claim 19, wherein R₁, R₂, R₃ and R₄ are identical.21. The method according to claim 19, wherein R₁, R₂, R₃ and R₄represent a linear (C₁-C₆)alkyl group.
 22. The method according to claim19, wherein R₁, R₂, R₃ and R₄ are chosen from methyl, ethyl, propyl andbutyl groups.
 23. The method according to claim 19, wherein m is equalto n.
 24. The method according to claim 19, in which m and n are chosenfrom 1, 2 and
 3. 25. The method according to claim 19, wherein Col⁽⁻⁾_(m) comprises: at least one sulphonate group and at least one(hetero)aryl group, wherein the at least one sulphonate group isdirectly connected to a (hetero)aryl group; and optionally at least oneanionic group G⁻, wherein G⁻, which is identical or different,represents an anionic group chosen from alkoxide O⁻, thiolate S⁻,carboxylate and thiocarboxylate C(Q)Q′⁻, wherein Q and Q′, which areidentical or different, are chosen from oxygen and sulphur atoms. 26.The method according to claim 25, wherein G⁻ is a carboxylate.
 27. Themethod according to claim 19, wherein Col⁽⁻⁾ _(m) comprises at least onecarboxylate group and at least one (hetero)aryl group, wherein the atleast one carboxylate group is directly connected to a (hetero)arylgroup.
 28. The method according to claim 19, wherein the anionic directdye is chosen from acid nitro direct dyes, acid azo dyes, acid azinedyes, acid triarylmethane dyes, acid indoamine dyes, acid anthraquinonedyes, indigoids and acid natural dyes, each of these dyes having atleast one sulphonate or carboxylate group having the cationic counterionR₁R₂R₃R₄N⁺.
 29. The method according to claim 19, wherein the at leastone anionic dye of formula (I) is chosen from the dyes of followingformulae (II), (II′), (III), (III′), (IV), (IV′), (V), (V′), (VI),(VII), (VIII) and (IX): a) diaryl anionic azo dyes of formulae (II) or(II′):

wherein: R₇, R₈, R₉, R₁₀, R′₇, R′₈, R′₉ and R′₁₀, which are identical ordifferent, are chosen from: hydrogen atoms; alkyl groups; alkoxy groups,alkylthio groups; hydroxyl groups, mercapto groups; nitro groups,nitroso groups; R^(o)—C(X)—X′—, R^(o)—X′—C(X)″—, R^(o)—X′—C(X)—X″—,wherein R^(o) is chosen from hydrogen atoms alkyl groups, and arylgroups; and X, X′ and X″, which are identical or different, are chosenfrom oxygen atoms, sulphur atoms, and NR, wherein R is chosen fromhydrogen atoms and alkyl groups; M⁺(O)₂S(O⁻)—, wherein M⁺ is chosen fromhydrogen atoms, cationic counterions, and ammonium cationic counterionsR₁R₂R₃R₄N⁺; M⁺(O)CO⁻—; R″—S(O)₂—, wherein R″ is chosen from hydrogenatoms and alkyl, aryl, (di)(alkyl)amino and aryl(alkyl)amino groups;R′″-S(O)₂—X′—, wherein R′″ is chosen from alkyl groups and aryl groups,optionally substituted, and X′ is chosen from oxygen atoms, sulphuratoms, and NR, wherein R is chosen from hydrogen atoms and alkyl groups;(di)(alkyl)amino groups; aryl(alkyl)amino groups, optionally substitutedby at least one group chosen from nitro, nitroso, M⁺(O)₂S(O⁻)—, andalkoxy groups; optionally substituted heteroaryl groups; cycloalkylgroups; Ar—N═N—, wherein Ar is an optionally substituted aryl group; ortwo contiguous groups, R₇ with R₈, R₈ with R₉, R₉ with R₁₀, whichtogether form a fused benzo group A′; and R′₇ with R′₈ or R′₈ with R′₉or R′₉ with R′₁₀ together form a fused benzo group B′; wherein A′ and B′are optionally substituted by at least one group chosen from nitro;nitroso; M⁺(O)₂S(O⁻)—; hydroxyl; mercapto; (di)(alkyl)amino;R^(o)—C(X)—X′—; R^(o)—X′—C(X)—; R^(o)—X′—C(X)—X″—; Ar—N═N—; andaryl(alkyl)amino which is optionally substituted; W is chosen from sigmaa bonds, oxygen atoms, sulphur atoms, and divalent radicals i) —NR—,wherein R is chosen from hydrogen atoms and alkyl groups and ii)methylene —C(R_(a))(R_(b))—, wherein R_(a) and R_(b), which areidentical or different, are chosen from hydrogen atoms and aryl groups,or R_(a) and R_(b) form, together with the carbon atom to which they areattached, a spirocycloalkyl; wherein the formulae (II) and (II′)comprise at least one sulphonate radical R₁R₂R₃R₄N⁺(O)₂S(O⁻)— orcarboxylate radical R₁R₂R₃R₄N⁺(O)C(O⁻)— on one of the rings A, A′, B, B′or C; b) pyrazolone anionic azo dyes of formulae (III) and (III′):

wherein: R₁₁, R₁₂ and R₁₃, which are identical or different, are chosenfrom hydrogen atoms, halogen atoms, alkyl groups and M⁺(O)₂S(O⁻)—groups; R₁₄ is chosen from hydrogen atoms, alkyl groups and M⁺C(O)O⁻—groups; R₁₅ is a hydrogen atom; R₁₆ is an oxo group, wherein R′₁₆ isabsent or R₁₅ with R₁₆ together form a double bond; R₁₇ and R₁₈, whichare identical or different, are chosen from hydrogen atoms and groupschosen from: M⁺(O)₂S(O)—; and Ar—O—S(O)₂—, wherein Ar is an optionallysubstituted aryl group; R₁₉ and R₂₀, together form a double bond or anoptionally substituted benzo group D′; R′₁₆, R′₁₉ and R′₂₀, which areidentical or different, are chosen from hydrogen atoms, alkyl groups andhydroxyl groups; R₂₁ is chosen from hydrogen atoms, alkyl groups andalkoxy groups; R_(a) and R_(b), which are identical or different, whichare identical or different, are chosen from hydrogen atoms and arylgroups, or R_(a) and R_(b) form, together with the carbon atom to whichthey are attached, a spirocycloalkyl; Y is chosen from hydroxyl groupsand oxo groups;

is a single bond when Y is an oxo group and a double bond when Y is ahydroxyl group; wherein the formulae (III) and (III′) comprise at leastone sulphonate group R₁R₂R₃R₄N(O)₂S(O⁻)— on one of the rings D or E orcarboxylate group R₁R₂R₃R₄N⁺(O)C(O⁻)—; c) anthraquinone dyes of formulae(IV) and (IV′):

wherein: R₂₂, R₂₃, R₂₄, R₂₅, R₂₆ and R₂₇, which are identical ordifferent, are chosen from hydrogen atoms, halogen atoms and groupschosen from: alkyl; hydroxyl, mercapto; alkoxy, alkylthio; optionallysubstituted aryloxy and arylthio; aryl(alkyl)amino optionallysubstituted by at least one group chosen from alkyl and M⁺(O)₂S(O⁻)—;(di)(alkyl)amino; (di)(hydroxyalkyl)amino; and M⁺(O)₂S(O⁻)—; Z′ ischosen from hydrogen atoms and NR₂₈R₂₉ groups wherein R₂₈ and R₂₉, whichare identical or different, are chosen from hydrogen atoms and groupschosen from: alkyl; (poly)hydroxyalkyl; aryl, optionally substituted byat least one group chosen from alkyl, M⁺(O)₂S(O⁻)—, R^(o)—C(X)—X′—,R^(o)—X′—C(X)— and R^(o)—X′—C(X)—X″—; and cycloalkyl; Z is a groupchosen from hydroxyl and NR′₂₈R′₂₉; wherein the formulae (IV) and (IV′)comprise at least one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)—; d) nitrodyes of formulae (V) and (V′):

wherein: R₃₀, R₃₁ and R₃₂, which are identical or different, are chosenfrom hydrogen atoms, halogen atoms and groups chosen from: alkyl; alkoxyoptionally substituted by at least one hydroxyl group; alkylthiooptionally substituted by at least one hydroxyl group; hydroxyl,mercapto; nitro, nitroso; (poly)haloalkyl; R^(o)—C(X)—X′—,R^(o)—X′—C(X)—, R^(o)—X′—C(X)—X″—; M⁺(O)₂S(O⁻)—; M⁺(O)CO⁻—;(di)(alkyl)amino; (di)(hydroxyalkyl)amino; and heterocycloalkyl; R_(c)and R_(d), which are identical or different, are chosen from hydrogenatoms and alkyl groups; W is chosen from sigma σ bonds, oxygen atoms,sulphur atoms, and divalent radicals i) —NR—, wherein R is chosen fromhydrogen atoms and alkyl groups and ii) methylene —C(R_(a))(R_(b))—,wherein R_(a) and R_(b), which are identical or different, are chosenfrom hydrogen atoms and aryl groups, or R_(a) and R_(b) form, togetherwith the carbon atom to which they are attached, a spirocycloalkyl; ALKis a linear or branched divalent C₁-C₆alkylene group; n is 1 or 2; p isan integer ranging from 1 to 5; q is an integer ranging from 1 to 4; uis 0 or 1; when n has a value of 1, J is chosen from nitro and nitrosogroups; when n has a value of 2, J is chosen from oxygen atoms, sulphuratoms, and divalent —S(O)_(m)— radicals, wherein m is an integer whichis 1 or 2; M′ is chosen from hydrogen atoms and cationic counterions;

which is present or absent, is a benzo group optionally substituted byat least one R₃₀ group; wherein the formulae (V) and (V′) comprise atleast one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate groupR₁R₂R₃R₄N⁺(O)C(O⁻)—; e) triarylmethane dyes of formula (VI):

wherein: R₃₃, R₃₄, R₃₅ and R₃₆, which are identical or different, arechosen from hydrogen atoms alkyl groups, optionally substituted arylgroups, and optionally substituted arylalkyl groups; R₃₇, R₃₈, R₃₉, R₄₀,R₄₁, R₄₂, R₄₃ and R₄₄, which are identical or different, are chosen fromhydrogen atoms and groups chosen from: alkyl; alkoxy, alkylthio;(di)(alkyl)amino; hydroxyl, mercapto; nitro, nitroso; R^(o)—C(X)—X′—,R^(o)—X′—C(X)—, R^(o)—X′—C(X)—X″—, wherein R^(o) is chosen from hydrogenatoms, alkyl groups, and aryl groups, and X, X′ and X″, which areidentical or different, are chosen from oxygen atoms, sulphur atoms, andNR groups, wherein R is chosen from hydrogen atoms and alkyl groups;M⁺(O)₂S(O⁻)—, wherein M⁺ is chosen from hydrogen atoms, cationiccounterions, and ammonium cationic counterions R₁R₂R₃R₄N⁺; M⁺(O)CO⁻—; ortwo contiguous groups chosen from R₄₁ with R₄₂, R₄₂ with R₄₃, and R₄₃with R₄₄, which together form a fused benzo group I′; wherein I′ isoptionally substituted by at least one group chosen from nitro; nitroso;M⁺(O)₂S(O⁻)—; hydroxyl; mercapto; (di)(alkyl)amino; R^(o)—C(X)—X′—;R^(o)—X′—C(X)—; and R^(o)—X′—C(X)—X″—; wherein at least one of the ringsG, H, I or I′ comprises at least one sulphonate groupR₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate group R₁R₂R₃R₄N⁺(O)C(O⁻)—; f)xanthene-derived dyes of formula (VII):

wherein: R₄₅, R₄₆, R₄₇ and R₄₈, which are identical or different, arechosen from hydrogen atoms and halogen atoms; R₄₉, R₅₀, R₅₁ and R₅₂,which are identical or different, are chosen from hydrogen atoms,halogen atoms and groups chosen from: alkyl; alkoxy, alkylthio;hydroxyl, mercapto; nitro, nitroso; M⁺(O)₂S(O⁻)—, wherein M⁺ is chosenfrom hydrogen atoms and cationic counterions; and M⁺(O)CO⁻—; G is anoxygen atom; L is chosen from alkoxide M⁺O⁻ groups, thioalkoxide M⁺S⁻groups, and NR_(f) groups, wherein R_(f) is chosen from hydrogen atomsand alkyl groups; L′ is chosen from oxygen atoms, sulphur atoms andammonium groups N⁺R_(f)R_(g), wherein R_(f) and R_(g), which areidentical or different, are chosen from hydrogen atoms, alkyl groups,and aryl groups that are optionally substituted; Q and Q′, which areidentical or different, are chosen from oxygen atoms and sulphur atoms;and M⁺ is chosen from hydrogen atoms, cationic counterions, and ammoniumcationic counterions R₁R₂R₃R₄N⁺; wherein the formula (VII) comprises atleast one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate groupR₁R₂R₃R₄N⁺(O)C(O⁻)—; g) indole-derived dyes of formula (VIII):

wherein: R₅₃, R₅₄, R₅₅, R₅₆, R₅₇, R₅₈, R₅₉ and R₆₀, which are identicalor different, are chosen from hydrogen atoms and groups chosen from:alkyl; alkoxy, alkylthio; hydroxyl, mercapto; nitro, nitroso;R^(o)—C(X)—X′—, R^(o)—X′—C(X)—, R^(o)—X′—C(X)—X″—, wherein R^(o) ischosen from hydrogen atoms, alkyl groups, and aryl groups, and X, X′ andX″, which are identical or different, are chosen from oxygen atoms,sulphur atoms and NR groups, wherein R is chosen from hydrogen atoms andalkyl groups; M⁺(O)₂S(O⁻)—, wherein M⁺ is chosen from hydrogen atoms,cationic counterions, and ammonium cationic counterions R₁R₂R₃R₄N⁺; andM⁺(O)CO⁻—; G is an oxygen atom; and R_(i) and R_(h), which are identicalor different are chosen from hydrogen atoms and alkyl groups; whereinthe formula (VIII) comprises at least one sulphonate groupR₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate group R₁R₂R₃R₄N⁺(O)C(O⁻)— h)quinoline-derived dyes of formula (IX):

wherein: R₆₁ is chosen from hydrogen atoms, halogen atoms, and alkylgroups; R⁶², R₆₃ and R₆₄, which are identical or different, are chosenfrom hydrogen atoms and M⁺(O)₂S(O⁻)— groups, wherein M⁺ is chosen fromhydrogen atoms, cationic counterions, and ammonium cationic counterionsR₁R₂R₃R₄N⁺; or R₆₁ with R₆₂ or R₆₁ with R₆₄ together form a benzo groupoptionally substituted by at least one M⁺(O)₂S(O⁻)— groups; wherein theformula (IX) comprises at least one sulphonate groupR₁R₂R₃R₄N⁺(O)₂S(O⁻)—.
 30. The method according to claim 29, wherein theat least one anionic dye of formula (I) is chosen from formulae (II),(III), and (IV).
 31. The method according to claim 19, wherein the atleast one anionic dye of formula (I) is chosen from formulae (IIa),(IIIa) and (IVa):

wherein in formula (IIa): R₇, R₈, R₉, R₁₀, R′₇, R′₈, R′₉ and R′₁₀, whichare identical or different, are chosen from hydrogen atoms and groupschosen from: hydroxyl; nitro, nitroso; (di)(alkyl)amino; M⁺(O)₂S(O⁻)—,wherein M⁺ is chosen from hydrogen atoms, cationic counterions, andammonium cationic counterions R₁R₂R₃R₄N⁺; and Ar—N═N—, wherein Ar is anoptionally substituted aryl group; two contiguous groups chosen from R₇with R₈, R₈ with R₉, and R₉ with R₁₀, that together form a fused benzogroup A′; and two contiguous groups chosen from R′₁₇ with R′₈, R′₈ withR′₉, and R′₉ with R′₁₀, that together form a fused benzo group B′;wherein A′ and B′ are optionally substituted by at least one groupchosen from M⁺(O)₂S(O⁻)—; hydroxyl; and Ar—N═N—; wherein the formula(IIa) comprises at least one sulphonate radical R₁R₂R₃R₄N⁺(O)₂S(O⁻)— orcarboxylate radical R₁R₂R₃R₄N⁺(O)C(O⁻)— on one of the rings A, A′, B,B′;

wherein: R₁₁, R₁₂ and R₁₃, which are identical or different, are chosenfrom hydrogen atoms, halogen atoms alkyl groups, and M⁺(O)₂S(O⁻)—groups, wherein M⁺ is chosen from hydrogen atoms, cationic counterions,and ammonium cationic counterions R₁R₂R₃R₄N⁺; R₁₄ is chosen fromhydrogen atoms, alkyl groups, and M⁺C(O)O⁻— groups; R₁₆, R₁₇, R₁₈, R₁₉and R₂₀, which are identical or different, are chosen from hydrogenatoms, alkyl groups, hydroxyls, and M⁺(O)₂S(O⁻)— groups; Y is chosenfrom hydroxyl groups and oxo groups;

represents a single bond when Y is an oxo group and represents a doublebond when Y is a hydroxyl group; wherein the formula (Ilia) comprises atleast one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— on one of the rings D orE or carboxylate group R₁R₂R₃R₄N⁺(O)C(O⁻)—;

wherein: Z′ is an NR₂₈R₂₉ group, wherein R₂₈ is chosen from hydrogenatoms and alkyl groups, and R₂₉ is an optionally substituted aryl group;Z is chosen from hydroxyl groups and NR′₂₈R′₂₉, wherein R′₂₈ is chosenfrom hydrogen atoms and alkyl groups, and R′₂₉ is an optionallysubstituted aryl group; wherein the formula (IVa) comprises at least onesulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)—.
 32. The method according to claim19, wherein the at least one anionic dye of formula (I) is chosen from:

wherein M+, which is identical or different, is chosen from hydrogenatoms, cationic counterions, and ammonium cationic counterionsR₁R₂R₃R₄N⁺, wherein at least one of the cationic counterions is acationic counterion R₁R₂R₃R₄N⁺.
 33. A method for dyeing and lighteningdark keratinous fibers having a height of tone of less than or equal to6, comprising applying to the fibers, a composition comprising at leastone fluorescent anionic dye of formula (I)

and optical isomers, geometric isomers, and solvates thereof, wherein informula (I): R₁, R₂, R₃ and R₄, which are identical or different, arechosen from i) (C₁-C₂₀)alkyls; and ii) (C₂-C₂₀)alkenyls; it beingpossible for the alkyl or alkenyl group of the groups of i) and ii) tobe interrupted by at least one identical or different heteroatoms chosenfrom oxygen, sulphur, and N(Rα), wherein Rα is chosen from hydrogenatoms and alkyl groups; Col⁽⁻⁾ _(m) represents the anionic part of theanionic dye comprising at least one sulphonate group and/or at least onecarboxylate group and wherein m is the anionic charges; wherein m and n,which are identical or different, represent an integer ranging from 1 to10; wherein when the anionic part of the anionic dye comprises asulphonate group or a carboxylate group, then m=n=1; and when theanionic part of the anionic dye comprises anionic groups other than asulphonate or carboxylate group, the anionic part is combined with atleast one cationic counterion, organic, inorganic or R₁R₂R₃R₄N⁺, makingit possible to achieve electrical neutrality of the formula (I).
 34. Themethod according to claim 33, wherein the composition comprises at leastone fluorescent anionic dye chosen from xanthene derivatives (VII):

wherein: R₄₅, R₄₆, R₄₇ and R₄₈, which are identical or different, arechosen from hydrogen atoms and halogen atoms; R₄₉, R₅₀, R₅₁, and R₅₂,which are identical or different, are chosen from hydrogen atoms,halogen atoms and groups chosen from: alkyl; alkoxy, alkylthio;hydroxyl, mercapto; nitro, nitroso; M⁺(O)₂S(O⁻)—, wherein M⁺ is chosenfrom hydrogen atoms and cationic counterions; and M⁺(O)CO⁻—; G is anoxygen atom; L is chosen from alkoxide M⁺O⁻ groups, thioalkoxide M⁺S⁻groups, and NR_(f) groups, wherein R_(f) is chosen from hydrogen atomsand alkyl groups; L′ is chosen from oxygen atoms, sulphur atoms andammonium groups N⁺R_(f)R_(g), wherein R_(f) and R_(g), which areidentical or different, are chosen from hydrogen atoms, alkyl groups,and aryl groups that are optionally substituted; Q and Q′, which areidentical or different, are chosen from oxygen atoms and sulphur atoms;and M⁺ is chosen from hydrogen atoms, cationic counterions, and ammoniumcationic counterions R₁R₂R₃R₄N⁺; wherein the formula (VII) comprises atleast one sulphonate group R₁R₂R₃R₄N⁺(O)₂S(O⁻)— or carboxylate groupR₁R₂R₃R₄N⁺(O)C(O⁻)—.
 35. The method according to claim 33, wherein thekeratinous fibers having a height of tone of less than or equal to 4.36. The method according to claim 33, wherein the at least onefluorescent anionic dye is within the range of the orangey colors. 37.An anionic dye of formula (I):

and optical isomers, geometric isomers, and solvates thereof, wherein informula (I): R₁, R₂, R₃ and R₄, which are identical or different, arechosen from i) (C₁-C₂₀)alkyls; and ii) (C₂-C₂₀)alkenyls; it beingpossible for the alkyl or alkenyl group of the groups of i) and ii) tobe interrupted by at least one identical or different heteroatoms chosenfrom oxygen, sulphur, and N(Rα), wherein Rα is chosen from hydrogenatoms and alkyl groups; Col⁽⁻⁾ _(m) represents the anionic part of theanionic dye comprising at least one sulphonate group and/or at least onecarboxylate group and wherein m is the anionic charges; wherein m and n,which are identical or different, represent an integer ranging from 1 to10; wherein when the anionic part of the anionic dye comprises asulphonate group or a carboxylate group, then m=n=1; when the anionicpart of the anionic dye comprises anionic groups other than a sulphonateor carboxylate group, the anionic part is combined with at least onecationic counterion, organic, inorganic or R₁R₂R₃R₄N⁺, making itpossible to achieve electrical neutrality of the formula (I), and theanionic dye of formula (I) is different from the dyes of formulae (a) to(u):


38. A dyeing composition for dyeing keratinous fibers, said compositioncomprising at least one anionic dye of formula (I):

and optical isomers, geometric isomers, and solvates thereof, wherein informula (I): R₁, R₂, R₃ and R₄, which are identical or different, arechosen from i) (C₁-C₂₀)alkyls; and ii) (C₂-C₂₀)alkenyls; it beingpossible for the alkyl or alkenyl group of the groups of i) and ii) tobe interrupted by at least one identical or different heteroatoms chosenfrom oxygen, sulphur, and N(Rα), wherein Rα is chosen from hydrogenatoms and alkyl groups; Col⁽⁻⁾ _(m) represents the anionic part of theanionic dye comprising at least one sulphonate group and/or at least onecarboxylate group and wherein m is the anionic charges; wherein m and n,which are identical or different, represent an integer ranging from 1 to10; wherein when the anionic part of the anionic dye comprises asulphonate group or a carboxylate group, then m=n=1; when the anionicpart of the anionic dye comprises anionic groups other than a sulphonateor carboxylate group, the anionic part is combined with at least onecationic counterion, organic, inorganic or R₁R₂R₃R₄N⁺, making itpossible to achieve electrical neutrality of the formula (I), and theanionic dye of formula (I) is different from the dyes of formulae (a) to(u):